Just to pitch into this... when I started my IR, my instructor said to me "everyone thinks an IR is about flying approaches, but it isn't, it's about controlling the aircraft using instruments". We then proceeded to fly several hours under the hood doing just that, before we ever went near an approach. I was frustrated at the time but of course he was right.
If you can't control an aircraft using instruments during cruise flight, you sure as hell won't be able to fly an approach when you are (relatively speaking) overwhelmed with frequent changes of heading and altitude, talking to ATC, getting the aircraft configured for landing...